Method for alleviating partial inactivation of color couplers

Abstract

A method is disclosed for alleviating the partial inactivation of color couplers caused by adventitious reaction with vapors of formaldehyde or a vinyl monomer. Partial inactivation is evidenced by decreased spectral absorptivity of the dye produced by reaction of the color coupler with color dye-forming compounds, such as oxidized photographic color developing agents. The method comprises contacting a partially inactivated coupler with an aqueous solution comprising an oxidizing agent and an oxidation accelerator.

What is claimed is: 
     
       1. A method for alleviating partial inactivation of a color coupler, said partial inactivation having been caused by reaction of the color coupler with formaldehyde or a vinyl monomer, said method comprising contacting the color coupler with an aqueous solution comprising hydrogen peroxide or deuterium peroxide as an oxidizing agent and an oxidation accelerator capable of acting as a potential mediator for transferring electrons between the oxidizing agent and the color coupler. 
     
     
       2. A method for increasing the spectral absorptivity of a dye formed by the reaction of an oxidized primary aromatic amino color developing agent with a color coupler which has been partially inactivated by reaction with formaldehyde or a vinyl monomer, said method comprising contacting said dye with an aqueous solution comprising hydrogen peroxide or deuterium peroxide as an oxidizing agent and an oxidation accelerator capable of acting as a potential mediator for transferring electrons between the oxidizing agent and the coupler portion of the dye. 
     
     
       3. In a method for producing a dye image in an imagewise exposed photographic element comprising a silver halide and a color coupler susceptible to partial inactivation by reaction with formaldehyde or a vinyl monomer, said method comprising the steps of: (a) contacting said element with a primary aromatic amino color developing agent to produce within the element a silver image and an associated dye image formed by reaction of said color coupler with oxidized color developing agent, and   (b) contacting said element with a bleaching agent and a fixing agent either simultaneously or successively in order to remove unexposed silver halide and said silver image from said element while retaining said dye image,   the improvement wherein step (b) is followed by:   (c) contacting said element with an aqueous solution comprising hydrogen peroxide or deuterium peroxide as an oxidizing agent and an oxidation accelerator capable of acting as a potential mediator for transferring electrons between the oxidizing agent and the color coupler portion of the dye image in order to alleviate said partial inactivation of said color coupler.   
     
     
       4. The method of claims 1, 2, or 3 wherein said oxidizing agent is hydrogen peroxide. 
     
     
       5. The method of claim 4 wherein said aqueous solution comprises from about 0.3 percent to about 0.6 percent by weight of said hydrogen peroxide. 
     
     
       6. The method of claims 1, 2, or 3 wherein said aqueous solution comprises more than 0 percent and less than 0.001 percent by weight of said oxidation accelerator. 
     
     
       7. The method of claims 1, 2, or 3 wherein said oxidation accelerator is potassium ferricyanide, sodium anthraquinonedisulfonate, or disodium iron ethylenediaminetetraacetic acid. 
     
     
       8. The method of claims 1, 2, or 3 wherein said aqueous solution comprises from about 0.0001 percent to about 0.0003 percent by weight of said oxidation accelerator, and said oxidation accelerator comprises potassium ferricyanide. 
     
     
       9. The method of claims 1, 2, or 3 wherein said aqueous solution comprises formaldehyde. 
     
     
       10. The method of claims 1, 2, or 3 wherein said aqueous solution comprises a wetting agent. 
     
     
       11. The method of claims 1, 2, or 3 wherein said aqueous solution comprises a pH buffer. 
     
     
       12. The method of claim 3 wherein said method comprises drying said photographic element after carrying out the steps described in claim 3. 
     
     
       13. The method of claim 12 wherein said drying is carried out at a temperature of from about 24° C. to about 70° C. 
     
     
       14. The method of claim 3 wherein said bleaching agent is incapable of overcoming partial inactivation of said color coupler caused by reaction of the color coupler with formaldehyde or a vinyl monomer. 
     
     
       15. The method of claim 14 wherein said bleaching agent comprises iron ammonium ethylenediaminetetraacetic acid. 
     
     
       16. The method of claims 1, 2, or 3 wherein said color coupler comprises a pyrazolone. 
     
     
       17. In a method for producing a dye image in an imagewise exposed photographic element comprising a silver halide and a color coupler susceptible to partial inactivation by reaction with formaldehyde or a vinyl monomer, said method comprising the steps of: (a) contacting said element with a primary aromatic amino color developing agent to produce within the element a silver image and an associated dye image formed by reaction of said color coupler with oxidized color developing agent, and   (b) contacting said element with a bleaching agent and a fixing agent either simultaneously or successively in order to remove unexposed silver halide and said silver image from said element while retaining said dye image,   the improvement wherein step (b) is followed by:   (c) contacting said element with an aqueous solution comprising from about 0.3 percent to about 0.6 percent by weight of hydrogen peroxide as an oxidizing agent and potassium ferricyanide, sodium anthraquinonedisulfonate, or disodium iron ethylenediaminetetraacetic acid as an oxidation accelerator in order to alleviate said partial inactivation of said color coupler.